This application pertains to the art of press fabrication and more particularly to control of a pressing operation or run. The invention is particularly applicable to continuous, real-time monitoring of press operation and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications such as in any system in which stress or strain characteristics are advantageously measured or monitored continuously, accurately, and in real time.
A substantial number of manufactures are formed through punching or press operations. In such an operation, raw material, such as steel or other malleable metal is subjected to a high-force blow from a die. Application of insufficient force will result in underformed or malformed workpieces. Excessive force may damage the workpiece or the press itself. Further, excessive force may be indicative that the press is being operated at too high a level. That is, the particular press operation may be more suitable for a press of higher capacity or force.
Some earlier systems have attempted to address these concerns by utilization of press housing strain characteristics to determine force of a particular press blow. A mechanical strain gauge was affixed to a press housing. The strain gauge would be manually reset and a reading obtained after a single blow of a press operation. The strain gauge reading obtained from this blow would be utilized to determine whether the press was utilized beyond capacity during setup of a run. Typically, several sample workpieces would be so measured, with a manual reset of the strain gauge between each workpiece.
These systems provide useful information during the set up operation of a particular workpiece run. However, the mechanical nature of the strain gauge is utilized and the manual reset requirements limited its utility to such set ups.
The present invention contemplates a new and improved press monitor which provides not only intermittent or set-up press characteristics, that provides continuous, real-time and non-supervised monitoring and control of a press operation.